Spark-timer for internal-combustion gas-engines.



0. L. BRAINARD. SPARK TIMER FOR INTERNAL (JOMBUSTIQN GAS ENGINES APPLICATION FILED 120, 1909, v 941,556., Patented Nov, 30, 1909.

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engines.

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more particularly to a timing device for the spark ignition of internal combustion gas Heretoftora it has been proposed to effect the make and break of the sparking circuit of a engine by means of a contact ring mounted eccentrically with respect to the engine shaft and-movable into engagement with a contact member concentric with said shaft to intermittently close the circuit. Giving .to the sliding movement or the contact ring, the lattersoon becomes worn and renders the timer practically useiess for the purpose designed. lit has also been proposed to make the movable contact member in-the form of a wheel or roller which frictionallyengages a sectional contactring for intermittently closing the circuit to the battery. This ty e of timer is also detective,

in that the roler soon becomes fiat and the track or sectional contact member worn or otherwise impaired, thus preventing a good electrical contact between, the parts and causing the sparking device to miss fire.

.The object of the present invention is positively to insure a good electrical contact between the relatively stationary and movable members by makingnne of said contacts in the form of spur gear and providing the other wit internal teeth which engage the teeth on the spur gear'to auto-. matically close the circuit'at predetermined intervals.

Further objects and advantages will appear in the ioilowing description; itbeing understood that various changes int'orm, proportions and minor details or. construction may be resorted towithin the scope of the appeiided claims.

in the accompanying drawings forming a partoi this specification :--Figure 1 is a top plan view of a timin device constructed in accordance with my invention. Fig. 2 is a vertical sectional view of the same; Fig. 3

is an er a n upper end oi the post or stub shait. Flg.

' ,ecineation of Letters Patent.

stationary member, ,member 6' to rotate with'the ed detail perspective view of the Pat ented Norm 3th January 5th, 1969. Serial No. d?3,288.

i is a. perspective view of the slide and stop block-removed from the post.

Similar numerals of reference indicate corresponding parts in all of the figures or the drawings.

The improved timing mechanism forming the subject matter or" the present invention includes a stationary member 5 and a movable member G, the latter being provided with a socket 7 for the reception of the adjacentend of the cam shaft 8 of an internal combustion engine (not shown).

The movable member '6 is keyed to the shaft 8 and provided with a circular head 9 1which engages a correspondingly shaped seat 10 formed in the adjacent end of the thereby to permit the shaft and relatively to the member 5.

The lower end of the stationary member 5 is provided with a sleeve 11 which telescopes the member. 6, while the upper end thereof is formed with a peripheral. flange 12 which serves as a support for a sectional internal gear 13 constituting the stationary contact of the timing device, the movable contact being in the form of a spur gear 1 mounted for rotation with the member 6.

The internal gear 13 is secured to the relatively stationary member 5 by screws or similar fastening devices 15, said internai gear being. formed with oppositely disposed relatively short segments 16 insulated from the-adjacent portion of the gear and also from the stationary member 5 by a strip of suitable insulating material 15', there be ing binding screws 17 threaded in the seg-.

ments 16, as shown.

The head 9 of the movable member 6 is provided"with'atransversely disposed slot 18, preferably dove-tailed in cross section and in which is slidably mounted a correcorrespondingly. dovetailed block or 19 carrying a pm 20, which latter forms the axis ot the spur gear 14:, as shown.

Seated in an opening 21 in one end of the slide 19 is a coiled spring 22 the opposite end of which bears against a stop block carried by the head 9 and forms a closure for one end of the groove 18.

The function of the spring 22 is normally and yieldabiy to support the teeth or? the spur gear 14 inengagen ent with the teeth of the internal gear it, thereby to insure a good electrical contact between the parts and prevent the sparking mechanism from missing tire. The wires 24; are connected With the adjacentbinding screws 17 and are both grounded preferably on the engine frame, there being a battery 25 and the usual in duction coil 26 included in-the circuit for actuating the sparker, indicated at 27. Thus it will be seen that as the shaft 8 revolves the spur gear 1 Will engage the teeth of the internal gear 13 and as the gear passes the segments 16 the teeth on the gear and segments will interengage thus closing the circuitthrough said gear, movable member on post 6 and frame to the battery and thence back to the adjacent binding post.

A lever 30 is prererably secured to the stationary member-so that the latter may be rotated with respect to the movable memher when it is desired to change the timing of the make and breal v It will here be noted that the sha'tt 8 .15

arranged concentric with the teeth of the gear 18, while the spur gear 14: is eccentrically mounted with respect to the longitudinal axis of the shaft 8 so as to be in a position to engage the teeth on the gear 13, as the shaft revolves. It will also be noted that the spring 22 by engagement with the slide 19 serves to normally and yicldably support the teeth of the spur gear in engagement with the teeth on the.

internal gear 13 thus not only insuring a good contact between the parts but scrvlng to assist in ln'evcnting mutilation or 8X-' cessive wear on the teeth of said gear.

The timing mechanism shown and described is particularly designed for a twocylindcr engine but it will of course be understood that by changing the number of contacts or segments in the internal gear, the device may be used with equally a pin at. one end of the slide disposed parallel Withthe axis of the member, a spur gear rotatably mounted on saidlpin. and meshing with the internal gear on the sta tionary member, and means between the slide and the end of the slot for holding the slide normally projected to maintain the gears in mesh.

2. A spark timing device including relatively stationary and movable members, one 0t which is formed with a seating recess constituting a bearing and provided with an internalgear having a'series of insulated segmentsconstituting contacts, the other member being provided with an enlarged head journaled in said seating recess having a transverse slot formed therein, a slide mounted in said slot and provided with a pin, a block forming a closure for one end of the slot-and contorn'iing to and adapted to bear against the wall of the scating recess, aspur gear mounted for rotation on the pin, and means interposed between the block and slide for yieldably supporting the spur gear in engagement with the teeth .on the internal gear.

3. A spark timing device including relatively stationary and movable members one of which is provided with a seating recess, an internal gear carried-by the stationary member and provided With one or more toothed segments constituting contacts, a movable member having an enlarged head journaled in said seating recess and provided with a transverse slot, a slide arranged Within said slot and provided with a pin, a spur gear mounted for rotation on said pin and adapted to engage the teeth on the internal gear, said spur gear being disposed eccentrically with respect to the longitudinal axis of the movable member, a stop forming a closure for one end of the slot and conforming to and bearing against the interior Wall of the seating recess, and a spring interposed between the stop and slide for normally and yicldably supporting the spur gear in engagement with the teeth on the internal gear.

in testimony that I claim the foregoing as my own, I have hereto atlixed my signature in the presence of two witnesses.

OMAR LO VAL BR.-ilNARD. W it ncsses:

Enw. S. CnnnA'r'rUN, James Gnnnns. 

